webpack/lib/ContextModuleFactory.js

Packs CommonJs/AMD modules for the browser. Allows to split your codebase into multiple bundles, which can be loaded on demand. Support loaders to preprocess files, i.e. json, jade, coffee, css, less, ... and your custom stuff.

/*
	MIT License http://www.opensource.org/licenses/mit-license.php
	Author Tobias Koppers @sokra
*/
var async = require("async");
var path = require("path");

var Tapable = require("tapable");
var ContextModule = require("./ContextModule");
var ContextElementDependency = require("./dependencies/ContextElementDependency");

function ContextModuleFactory(resolvers) {
	Tapable.call(this);
	this.resolvers = resolvers;
}
module.exports = ContextModuleFactory;

ContextModuleFactory.prototype = Object.create(Tapable.prototype);
ContextModuleFactory.prototype.create = function(context, dependency, callback) {
	this.applyPluginsAsyncWaterfall("before-resolve", {
		context: context,
		request: dependency.request,
		recursive: dependency.recursive,
		regExp: dependency.regExp
	}, function(err, result) {
		if(err) return callback(err);

		// Ignored
		if(!result) return callback();

		var context = result.context;
		var request = result.request;
		var recursive = result.recursive;
		var regExp = result.regExp;

		var loaders, resource, loadersPrefix = "";
		var idx = request.lastIndexOf("!");
		if(idx >= 0) {
			loaders = request.substr(0, idx+1);
			for(var i = 0; i < loaders.length && loaders[i] === "!"; i++) {
				loadersPrefix += "!";
			}
			loaders = loaders.substr(i).replace(/!+$/, "").replace(/!!+/g, "!");
			if(loaders === "") loaders = [];
			else loaders = loaders.split("!");
			resource = request.substr(idx+1);
		} else {
			loaders = [];
			resource = request;
		}

		async.parallel([
			this.resolvers.context.resolve.bind(this.resolvers.context, context, resource),
			async.map.bind(async, loaders, this.resolvers.loader.resolve.bind(this.resolvers.loader, context))
		], function(err, result) {
			if(err) return callback(err);

			this.applyPluginsAsyncWaterfall("after-resolve", {
				loaders: loadersPrefix + result[1].join("!") + (result[1].length > 0 ? "!" : ""),
				resource: result[0],
				recursive: recursive,
				regExp: regExp
			},  function(err, result) {
				if(err) return callback(err);

				// Ignored
				if(!result) return callback();

				return callback(null, new ContextModule(this.resolveDependencies.bind(this), result.resource, result.recursive, result.regExp, result.loaders));
			}.bind(this));
		}.bind(this));
	}.bind(this));
};

ContextModuleFactory.prototype.resolveDependencies = function resolveDependencies(fs, resource, recursive, regExp, callback) {
	(function addDirectory(directory, callback) {
		fs.readdir(directory, function(err, files) {
			if(!files || files.length === 0) return callback();
			async.map(files, function(seqment, callback) {

				var subResource = path.join(directory, seqment)

				fs.stat(subResource, function(err, stat) {
					if(err) return callback(err);

					if(stat.isDirectory()) {

						if(!recursive) return callback();
						addDirectory.call(this, subResource, callback);

					} else if(stat.isFile()) {

						var obj = {
							context: resource,
							request: "." + subResource.substr(resource.length).replace(/\\/g, "/")
						};
						this.applyPluginsAsyncWaterfall("alternatives", [obj], function(err, alternatives) {
							alternatives = alternatives.filter(function(obj) {
								return regExp.test(obj.request);
							}).map(function(obj) {
								var dep = new ContextElementDependency(obj.request);
								dep.optional = true;
								return dep;
							});
							callback(null, alternatives);
						});

					} else callback();

				}.bind(this));

			}.bind(this), function(err, result) {
				if(err) return callback(err);

				if(!result) return callback(null, []);

				callback(null, result.filter(function(i) { return !!i; }).reduce(function(a, i) {
					return a.concat(i);
				}, []));
			});
		}.bind(this));
	}.call(this, resource, callback));
};